INFO: Data Access Objects Have Properties Based on Database Type (129732)

MORE INFORMATION

The built-in properties are available in the Properties collection for all databases including Microsoft Access, Btrieve, dBASE, Microsoft FoxPro, Paradox, and ODBC client-server databases such as SQL Server. For example, the following built-in properties are available in the Properties collection of the TableDef object (using DAO version 3.0):

    Name            SourceTableName
    Updatable       RecordCount
    DateCreated     ValidationRule
    LastUpdated     ValidationText
    Connect         ConflictTable
    Attributes
				

Additional application-defined properties are available for Microsoft Access databases. For a complete list of built-in and application-defined properties, please see the following topics in the Microsoft Access Help menu:

The application-defined properties will not be a part of the DAO's Properties collection until the values are changed from their default values. You can change an application-defined property default value by using Visual Basic code or by using the Microsoft Access design environment. In Visual Basic code, use the CreateProperty method just as you would to create user-defined properties.

Steps to Display the Properties Collection

1. Start a new project in Visual Basic. Form1 is created by default.
2. If using Visual Basic 5.0, establish a reference to DAO 3.5 by clicking References from the Project menu.
3. Add the following code to the Form1_Click procedure:

         Dim MyDB As Database
         Dim MySet As Recordset
         Dim MyProperty As Property
         Dim MyTableDef as TableDef
   
         ' Access database
         Set MyDB = DBEngine.Workspaces(0).OpenDatabase("biblio.mdb")
         Set MySet = MyDB.OpenRecordset("Authors", dbOpenTable)
         Set MyTableDef = MyDB("Authors")
   
         'display properties collection for Field
         For Each MyProperty In MySet(0).Properties
            List1.AddItem MyProperty.Name
         Next
   
         'display properties collection for Recordset
         For Each MyProperty In Myset.Properties
            List2.AddItem MyProperty.Name
         Next
   
         'display properties collection for Tabledef
         For Each MyProperty In MyTableDef.Properties
            List3.AddItem MyProperty.Name
         Next
   
         'Append an application-defined TableDef property by
         'changing its default value so it appears in the list
         On Error GoTo myerr:     'if RowHeight property exists trap error
         Set MyProperty = MyTableDef.CreateProperty("RowHeight")
         MyProperty.Type = dbinteger
         MyProperty.Value = 9
         MyTableDef.Properties.Append MyProperty
   
         myerr:
         MsgBox("RowHeight Property already exists, Please create another")
   
         'Print list again to see that RowHeight is displayed
         For Each MyProperty In MyTableDef.Properties
            List4.AddItem MyProperty.Name
         Next
         MySet.Close
         MyDb.Close
         On Error GoTo 0
   
   						

4. Add four list boxes (List1, List2, List3, and List4) to Form1.
5. Run the program.